1. Field of the Invention
The present invention relates to a weft tensioning device for use on shuttleless looms such as needle looms.
2. Prior Art
Needle looms use a reciprocating weft inserter or filling carrier to place a filling into a warp shed and to be withdrawn out of the warp shed during the crossing of the warps for a new shed. Such movement of the filling carrier for intermittent utilization of weft, that is, a sudden use of weft followed by a period of no use, results in maximum weft tension followed by a slackening of the weft. It is therefore necessary to maintain a constant tension of the weft in the vicinity of the filling carrier during the operation of the loom so as to keep evenness of the fabric being woven.
One proposal for constant weft tension has been a spring located between the weft yarn feeder and the filling carrier to take up slack in the weft. However, the spring cannot be responsive to high-speed operation of the filling carrier, thereby putting a sudden high strain on the weft. While the filling carrier is being reciprocated at high speeds, the weft can be broken, the eye in the filling carrier for the passage of the weft can be worn away soon, and the selvage knitting needle can be damaged.